Firestarter 4

Firestarter - Use a Fire Arrow (or the shotgun's incendiary ammo) to ignite six Corpse Bags. Arrow ammunition is limited when you first visit this area, so you can come back later (by Fast Travel) if you run out of ammo.

FIRESTARTER 4

Firestarter 4 is hanging past the second gate where two cultists (soon joined by a third) are talking next to a methane fumarole.